The effect of sensory deprivation in the reduction of pain in patients with chronic low-back pain.

Patients who suffer from persistent pain for prolonged periods of time (6 months or more) are often influenced to an increasing extent by psychological factors. Patients begin to focus on their pain as the problem rather than its physical origin. This study evaluated the effectiveness of sensory deprivation in reducing pain in patients with chronic low-back pain. Sixty patients were divided into two groups of 30 patients each: One group underwent 1 hour of sensory deprivation; the other received a lecture on relaxation skills. In the group receiving sensory deprivation, statistically significant decreases in pain and stiffness were noted. Sensory deprivation is an effective treatment to reduce pain and thus interrupt the pain cycle in patients with chronic low-back pain.

Choice of lasers for minimally invasive spinal surgery.

Recently, there has been increased interest in less invasive spinal surgery techniques. This has led to the development of procedures such as automated percutaneous lumbar discectomy and arthroscopic microdiscectomy. Lasers are now used in many areas of medicine and may have applications in minimally invasive spinal surgery. A number of different laser systems have been evaluated for their effectiveness in removing disc tissue in the laboratory, but technical problems have limited their clinical use. Only the Nd:YAG (1,064 nm and 1,320 nm) and KTP (532 nm) systems have been used clinically. Unsuccessful clinical results were obtained with the 1,064 nm Nd:YAG, whereas the other two systems appeared to produce results similar to the present mechanical systems but required less time for disc removal. This paper discusses considerations for choosing a laser system for spinal applications and reviews the work performed in this area.

Disc deterioration in low-back syndromes. A prospective, multi-center CT/discography study.

Disc deterioration and pain provocation in different low-back pain syndromes was studied using computed tomography (CT) discography. Data were prospectively collected for 300 patients (816 discs). Patients were classified by their pre-discography diagnosis of disc herniation (DH), degenerated disc (DD), lumbar syndrome (LS), lumbar radicular syndrome (LRS), or other. The CT/discograms were classified by discographic pain response, the amount of degeneration and annular disruption. Eighty-two percent of DH patients, 80% of DD, 56% of LS, and 59% of LRS patients had both positive discographic pain provocation and moderate or severe disc deterioration. The study indicates that intradiscal pathology plays a major role in nonspecific low-back pain syndromes.

Discitis after discography.

A series of nine patients with post-discography discitis were evaluated to help delineate the clinical course. The most consistent sign was the marked exacerbation of neck or back pain. This then was followed by an elevated sedimentation rate at an average of 20 days, followed by a positive bone scan at an average of 33 days. Of note is that seven patients initially had negative bone scans at an average of 18 days. Five out of nine patients had changes on plain roentgenograms between 14 and 51 days after discography. Magnetic resonance imaging was performed in six patients; two of these patients were scanned twice. Three scans were negative and five were positive (2 patients initially had negative scans that later became positive). The course of lumbar discitis ranged from 8 to 11 weeks, and cervical discitis from 6 to 7 weeks, with the latter usually resulting in spontaneous fusion.

Extraosseous spinal lesions mimicking disc disease.

To identify characteristics of patient presentation that would help distinguish extraosseous spinal tumors from the more common herniated disc, nine cases of intraspinal tumors were reviewed. These nine patients were identified in a group of 744 patients who presented with symptoms similar to disc herniation but failed to respond to conservative care and underwent spinal surgery. This study indicates that intraspinal tumor should be suspected in patients with the following characteristics: 1) painless neurological deficit; 2) night pain or pain which increases in the supine position; 3) pain disproportionate to that normally expected with lumbar disc disease; 4) no change in symptoms after successful surgery for herniated disc; 5) elevated spinal fluid protein; or 6) a teenager with symptoms of disc herniation. Myelography is an effective radiologic procedure for the diagnosis of spinal tumor but MRI should be equally effective if the procedure includes a scan of the conus as well as cauda equina.

Proplast reconstruction of iliac crest defects.

Proplast reconstruction of iliac crest defects resulting from bone grafts taken for anterior lumbar and cervical fusions is described. The procedure improves the cosmetic result, prevents postoperative muscle herniation and may decrease postoperative donor site pain. It is a simple procedure with low complication rate when performed in the manner described.

Anterior lumbar interbody fusion.

This is a report of 85 patients who underwent anterior lumbar interbody fusion (ALIF) for treatment of painful disc disruption (PDD) or symptomatic pseudarthrosis. The fusion rate was 80% by disc. The pseudarthrosis rate increased from 16% at L5-S1 to 21% and 31% at L4-5 and L3-4, respectively. There was a significant increase in pseudarthrosis rate in patients who smoked more than one pack per day. There was no difference in the fusion rate whether autogenous or cadaveric iliac crest graft or dowel versus tricortical block graft was used. Sixty-eight percent of patients were "able to work" after ALIF. The complication rate was low and retrograde ejaculation occurred in only one patient.

The effect of pulsed electromagnetic fields on the corrosion of a chromium-cobalt-nickel alloy orthopaedic implant.

In order to assess whether pulsed electromagnetic fields influence the rate of corrosion of orthopaedic metal implants, an alloy, called MP-35N, was exposed for 3 wk to a pulsed electromagnetic field. The results demonstrated that while there was a progressive release of the major constituents of MP-35N, i.e. cobalt (32.5%), nickel (36%), and chromium (20%), with time, corrosion was not significantly higher in the presence of the pulsed electromagnetic field when compared to that of the non-exposed pins. There was a significantly higher release of cobalt by the control pins after 5, 10, and 15 d incubation when compared with the pulsed pins. These findings were confirmed by SEM which demonstrated progressive surface corrosion with time and that the extent of corrosion was similar for both the control and pulsed pins. These results suggest that pulsed electromagnetic fields have no effect in promoting the surface corrosion of orthopaedic metallic implants.